Sensibilité à la récompense et à la punition chez les individus à risque de dépendance aux drogues et à l’alcool

Affiche présentée dans le cadre du colloque de l'ARC «Favoriser l’accès et le partage par la création d’un observatoire» lors du 86e Congrès de l'Acfas à l' Université du Québec à Chicoutimi (UQAC), les 7 et 8 mai 2018.Une minorité de consommateurs de drogues et d’alcool développe un trouble d’utilisation de substances (TUS). Les jeunes dont le niveau de comportements externalisés (EXT) est supérieur sont à risque plus élevé de TUS. Cette étude examine si les individus aux traits EXT élevés (eEXT), comparés à des EXT faibles (fEXT), ont une sensibilité altérée aux récompenses et punitions – par exemple, des évaluations sociales positives. Un total de 72 jeunes adultes (18-20 ans) suivis depuis la naissance ont été catégorisés comme fEXT (n=37) ou eEXT (n=35) selon leurs données (11-16 ans). Ils ont rempli l’Alcohol Use Disorders Identification Test (AUDIT), le Baratt Impulsiveness Scale, Sensitivity to Punishment & Reward Questionnaire, et la Substance Use Risk Profile Scale (SURPS). Des tests t pour échantillons indépendants et des corrélations de Pearson ont été utilisés pour examiner les différences entre les groupes et le lien entre les mesures comportementales. On constate chez les eEXT une sensibilité accrue aux récompenses et punitions, une impulsivité plus élevée et une consommation significativement supérieure de cannabis. Au total, la sensibilité aux récompenses corrèle avec l’AUDIT et la consommation de cannabis. Les individus avec eEXT sont plus sensibles aux récompenses, ce qui peut contribuer à leur développement de TUS. Ces résultats fournissent des informations importantes pour le développement de stratégies d’intervention précoces, la prévention et le traitement des TUS

A Systematic Review of Library Services Provision in Response to COVID-19 Pandemic

Objective – Libraries have had to temporarily shut their doors because of the COVID-19 pandemic, resulting in the provision of online and remote services. This review analyzed services offered by libraries, the technological tools used, and the challenges facing libraries during the pandemic. Methods – This study employed a systematic literature review, following the PRISMA checklist (Moher at al., 2009). The Building Blocks search strategy was employed to search for keywords of concepts in Library and Information Science Abstract (LISA), Library and Information Science Technology Abstract (LISTA), Library Science Database, Web of Science (WoS) core collections, and Google Scholar. A set of inclusion and exclusion criteria was pre-determined by the authors prior to database searching. Quality assessment of included studies was performed using the Mixed Methods Appraisal Tool (Hong et al., 2018). A tabular approach was used to provide a summary of each article allowing the synthesis of results, which led to the identification of eight broad categories of services provided by libraries in included studies. Results – The first set of searches from the 5 databases produced 3,499 results. After we removed duplicates and applied the inclusion and exclusion criteria based on titles and abstracts, 37 potentially relevant articles were identified. Further screening of the full-text led to the final inclusion of 23 articles used for the qualitative synthesis. The majority of the studies were conducted in the United States of America (n= 6, 26.1%), followed by India (n=4, 17%), and China (n=2, 8.7%). The remaining studies were carried out in United Kingdom, Ireland, Canada, Mexico, Romania, Czech Republic, Indonesia, Pakistan, Nigeria, Lesotho, and Zimbabwe. The most common method used in selected studies was the case study (n= 11, 48%), followed by survey (n=7, 30.4%), content analysis (n=4, 17.4%), and mixed methods (n=1, 4.3%). The majority of the studies were carried out in academic libraries (74%), while the rest were based on medical, public, and special libraries. Findings show that the majority of academic libraries in the included studies are providing and expanding access to electronic resources (n=16, 69.6%) and increasing open access resources and services (n=11, 47.8%). More so, most academic libraries are assisting in virtual education and teaching endeavors of faculty and students (n=13, 56.5%). In addition, some medical and public libraries are bolstering public health safety through health literacy (n=12, 52.2%), supporting research efforts, and engaging in virtual reference services, among others. In order to carry out these services, libraries are harnessing several educational, social networking, communication, and makerspaces technologies. Most of the libraries in the included studies reported budgetary challenges, and the need for new ICT infrastructure and Internet service as they move their services online. Conclusion – This review found that libraries are adapting in a number of ways to continue their roles in meeting patrons’ needs in spite of the growing challenges posed by COVID-19 restrictions and lockdown. For libraries to thrive in these trying times, there must be a well-structured approach to ensuring continuity of services. Libraries should prioritize the acquisition of electronic resources as well as increase their efforts to digitize resources that are only available in printed copies. As library services have predominantly shifted online, there should be concerted effort and support from government and funding agencies to equip libraries with the technological facilities needed to provide cutting-edge services. The quality assessment of the included studies shows that there is need for rigor and transparency in the methodological description of studies investigating library services provision in a pandemic. This review provides an overview of the ways libraries have responded to the challenges posed by a global pandemic, and hence will be of use and interest to all librarians especially those in health and academic sectors

Dopamine and light: Effects on facial emotion recognition

Bright light can affect mood states and social behaviours. Here, we tested potential interacting effects of light and dopamine on facial emotion recognition. Participants were 32 women with subsyndromal seasonal affective disorder tested in either a bright (3000 lux) or dim light (10 lux) environment. Each participant completed two test days, one following the ingestion of a phenylalanine/tyrosine-deficient mixture and one with a nutritionally balanced control mixture, both administered double blind in a randomised order. Approximately four hours post-ingestion participants completed a self-report measure of mood followed by a facial emotion recognition task. All testing took place between November and March when seasonal symptoms would be present. Following acute phenylalanine/tyrosine depletion (APTD), compared to the nutritionally balanced control mixture, participants in the dim light condition were more accurate at recognising sad faces, less likely to misclassify them, and faster at responding to them, effects that were independent of changes in mood. Effects of APTD on responses to sad faces in the bright light group were less consistent. There were no APTD effects on responses to other emotions, with one exception: a significant light × mixture interaction was seen for the reaction time to fear, but the pattern of effect was not predicted a priori or seen on other measures. Together, the results suggest that the processing of sad emotional stimuli might be greater when dopamine transmission is low. Bright light exposure, used for the treatment of both seasonal and non-seasonal mood disorders, might produce some of its benefits by preventing this effect

Dopamine and light:Effects on facial emotion recognition

Bright light can affect mood states and social behaviours. Here, we tested potential interacting effects of light and dopamine on facial emotion recognition. Participants were 32 women with subsyndromal seasonal affective disorder tested in either a bright (3000 lux) or dim light (10 lux) environment. Each participant completed two test days, one following the ingestion of a phenylalanine/tyrosine-deficient mixture and one with a nutritionally balanced control mixture, both administered double blind in a randomised order. Approximately four hours post-ingestion participants completed a self-report measure of mood followed by a facial emotion recognition task. All testing took place between November and March when seasonal symptoms would be present. Following acute phenylalanine/tyrosine depletion (APTD), compared to the nutritionally balanced control mixture, participants in the dim light condition were more accurate at recognising sad faces, less likely to misclassify them, and faster at responding to them, effects that were independent of changes in mood. Effects of APTD on responses to sad faces in the bright light group were less consistent. There were no APTD effects on responses to other emotions, with one exception: a significant light × mixture interaction was seen for the reaction time to fear, but the pattern of effect was not predicted a priori or seen on other measures. Together, the results suggest that the processing of sad emotional stimuli might be greater when dopamine transmission is low. Bright light exposure, used for the treatment of both seasonal and non-seasonal mood disorders, might produce some of its benefits by preventing this effect

A three-factor model of common early onset psychiatric disorders: temperament, adversity, and dopamine

Commonly comorbid early onset psychiatric disorders might reflect the varying expression of overlapping risk factors. The mediating processes remain poorly understood, but three factors show some promise: adolescent externalizing traits, early life adversity, and midbrain dopamine autoreceptors. To investigate whether these features acquire greater predictive power when combined, a longitudinal study was conducted in youth who have been followed since birth. Cohort members were invited to participate based on externalizing scores between 11 to 16 years of age. At age 18 (age 18.5 ± 0.6 y.o.), 52 entry criteria meeting volunteers had a 90-min positron emission tomography scan with [(18)F]fallypride, completed the Childhood Trauma Questionnaire, and were assessed with the Structured Clinical Interview for DSM-5. The three-factor model identified those with a lifetime history of DSM-5 disorders with an overall accuracy of 90.4% (p = 2.4 × 10(−5)) and explained 91.5% of the area under the receiver operating characteristic curve [95% CI: .824, 1.000]. Targeting externalizing disorders specifically did not yield a more powerful model than targeting all disorders (p = 0.54). The model remained significant when including data from participants who developed their first disorders during a three-year follow-up period (p = 3.5 × 10(−5)). Together, these results raise the possibility that a combination of temperamental traits, childhood adversity, and poorly regulated dopamine transmission increases risk for diverse, commonly comorbid, early onset psychiatric problems, predicting this susceptibility prospectively

Effect of (Z)-Isomer Content on [11C]ABP688 Binding Potential in Humans

Purpose: To determine how the low-affinity (Z)-isomer of the radiotracer [11C]ABP688 affects binding potential values in vivo in humans. Methods: High-resolution [11C]ABP688 PET scans were acquired on 74 healthy volunteers (25 male, 49 female, mean age 20 ± 3.0). The relative contents of (E)- and (Z)-isomers were determined prior to injection using analytical high-performance liquid chromatography [rt(E) = 10 min, rt(Z) = 8.5 min]. Mean binding potential [BPND = fND * (Bavail/KD)] values were calculated in the striatum, limbic regions, and prefrontal cortex using the simplified reference tissue model with cerebellar grey matter as reference. Results: Mean ± SD (E)-isomer content in [11C]ABP688 production was 92 ± 3.8% (range 78–97%). Percent (E)-isomer was positively correlated with BPND in the striatum (ρ = 0.28, p = 0.015) and limbic regions (ρ = 0.25, p = 0.036). In multiple regression analysis, sex (β = 0.39, p = 0.001) and (E)-isomer content (β = 0.23, p = 0.040) were significant predictors of BPND. Conclusions: Even modest levels of (Z)-[11C]ABP688 can reduce estimates of tracer binding in vivo. Future studies should use production methods that enrich levels of (E)-[11C]ABP688, report tracer isomer ratios, and account for this factor in their analyses

Novel trypanocidal inhibitors that block glycosome biogenesis by targeting PEX3–PEX19 interaction

Human pathogenic trypanosomatid parasites harbor a unique form of peroxisomes termed glycosomes that are essential for parasite viability. We and others previously identified and characterized the essential $\textit {Trypanosoma brucei}$ ortholog TbPEX3, which is the membrane-docking factor for the cytosolic receptor PEX19 bound to the glycosomal membrane proteins. Knockdown of TbPEX3 expression leads to mislocalization of glycosomal membrane and matrix proteins, and subsequent cell death. As an early step in glycosome biogenesis, the PEX3–PEX19 interaction is an attractive drug target. We established a high-throughput assay for TbPEX3–TbPEX19 interaction and screened a compound library for small-molecule inhibitors. Hits from the screen were further validated using an $\textit {in vitro}$ ELISA assay. We identified three compounds, which exhibit significant trypanocidal activity but show no apparent toxicity to human cells. Furthermore, we show that these compounds lead to mislocalization of glycosomal proteins, which is toxic to the trypanosomes. Moreover, NMR-based experiments indicate that the inhibitors bind to PEX3. The inhibitors interfering with glycosomal biogenesis by targeting the TbPEX3–TbPEX19 interaction serve as starting points for further optimization and anti-trypanosomal drug development